1. Technical Field
The present invention relates to endoscopic path planning, and more particularly, to endoscopic path planning using arteries as a surrogate for airways.
2. Discussion of the Related Art
Bronchoscopy with transbronchial biopsy (TBBx) is a diagnostic procedure in which a bronchoscope is inserted through the nose or mouth to collect multiple specimens of lung tissue. TBBx has been shown to be less traumatic to patients as compared to other methods of biopsying suspicious lung nodules, such as transthoracic needle biopsy (TTNBx) and video assisted thorascopic surgery (VATS). Until recently, however, TBBx has been limited to central nodules located close to major airways due to the size of the bronchoscope.
With the introduction of ultra-thin bronchoscopes, it is now possible to traverse peripheral airways to reach peripheral nodules in the lung. It is difficult, however, to plan a path through numerous branching airways to reach desired peripheral nodules. Even when using multi-slice computed tomography (CT) imaging systems capable of obtaining image volumes with an isotropic resolution of, for example, 0.5 mm, peripheral airways near the desired nodule may not be visible in the image data due to partial volume effects. Further, as airways branch repeatedly into smaller peripheral airways, the number of possible pathways increases exponentially, making it difficult to plan a pathway to a desired peripheral nodule.
Virtual endoscopy is a technique used to create visualizations from three-dimensional (3D) medical image scans that have a similar appearance to the images produced by current endoscopic procedures such as a bronchoscopy, angioscopy, and colonoscopy. These virtual endoscopic visualizations are a valuable aid to medical experts by showing them the path they will be traveling along during an actual bronchoscopy. However, virtual endoscopic techniques are limited by the resolution of the available 3D data, and are thus confined to central airways of the lung that are visible in the CT image data.
It has been shown that peripheral arteries are more visible than peripheral airways in CT image data because they do not suffer from the same degree of partial volume effects. In addition, it has been demonstrated in anatomic studies that airways and arteries parallel each other throughout the lung.
Accordingly, there is a need for a system and method for virtual endoscopic path planning that enables a medical expert such as a bronchoscopist to plan a path through numerous peripheral airways to reach desired peripheral nodules in a lung.